JP4218838B2 - Power supply system, power supply apparatus, and electronic circuit driving method - Google Patents

Description

  The present invention relates to a power supply and cooling technique, and more particularly to a power supply technique for a semiconductor integrated circuit.

  In LSI design, the miniaturization of the manufacturing process and the high integration of elements have further progressed, and it has become very important for LSI design to consider the amount of heat generated as the performance limit of the chip. When the chip becomes hot, malfunctions occur and long-term reliability decreases, so various countermeasures against heat generation are taken. For example, a method is used in which a heat sink is provided on the top of the chip to release heat generated from the chip.

In recent LSIs, particularly high-performance microprocessors, heat generation that cannot be completely removed by a heat sink can occur, so improvement of heat dissipation efficiency is a permanent issue.
Further, in LSI, there is a limit to the current capacity of a terminal connected to a substrate or the like, and there is a problem that the current density flowing through the terminal affects the reliability of the LSI, and power supply to the LSI is also important. As a technical issue.

  The present invention has been made in view of these problems, and an object thereof is to provide a power supply system capable of simultaneously supplying power while effectively cooling a semiconductor integrated circuit.

One embodiment of the present invention relates to a power supply system. This power supply system converts kinetic energy of a cooling medium for cooling an electronic circuit into electric energy, and drives the electronic circuit by the electric energy.
By selecting a conductive fluid as the cooling medium and applying a magnetic field to the conductive fluid, an electromotive force is generated by the interaction between the conductive fluid and the magnetic field based on Faraday's law of electromagnetic induction. By utilizing this electromotive force, the electronic circuit to be cooled can be driven.

  According to the present invention, it is possible to simultaneously supply power while effectively cooling a semiconductor integrated circuit.

  Before describing the details of the embodiment, an outline thereof will be described.

  One embodiment of the present invention relates to a power supply system. This power supply system includes: a base body having a flow path perforated; a pump that allows a conductive fluid to flow through the flow path formed in the base; and a magnet that applies a magnetic field perpendicular to the flow direction of the conductive fluid. And an anode and a cathode provided so as to sandwich the flow path on two opposing surfaces parallel to the direction of application of the magnetic field, and the semiconductor integrated circuit to be driven is driven by an electromotive force generated between the anode and the cathode To drive.

  According to this aspect, the conductive fluid and the magnetic field interact in the flow path inside the substrate, and an electromotive force is generated between the cathode and the anode based on Faraday's law of electromagnetic induction. Can be driven.

The substrate may be fixed in close contact with the semiconductor integrated circuit, the flow path may be perforated in a region close to the heat generating portion of the semiconductor integrated circuit, and may further include a cooling device for cooling the conductive fluid.
By bringing the substrate and the semiconductor integrated circuit into close contact with each other, heat generated in the semiconductor integrated circuit can be removed by the conductive fluid flowing through the flow path, and cooling and power supply can be performed simultaneously by cooling the conductive fluid with a cooling device. It can be carried out.

The flow path may have a microchannel structure, and a plurality of flow paths may be formed adjacent to each other in the magnetic field application direction.
By using a microchannel structure for the flow path, the heat transport efficiency of the conductive fluid can be increased, and the cooling efficiency of the semiconductor integrated circuit can be increased.

You may further provide the temperature detection part which detects the temperature of a semiconductor integrated circuit, and the cooling control part which controls the cooling capacity of a cooling device based on the temperature of the semiconductor integrated circuit detected by the temperature detection part.
Stable cooling can be performed by controlling the cooling device according to the temperature of the semiconductor integrated circuit and adjusting the temperature of the conductive fluid.

  The anode and the cathode may be connected to the power supply voltage terminal and the fixed voltage terminal of the semiconductor integrated circuit, respectively.

Each of the anode and the cathode is provided in parallel with the semiconductor integrated circuit, the anode is provided on the semiconductor integrated circuit side of the flow path, and the cathode is provided on the side of the flow path opposite to the semiconductor integrated circuit. Good.
By setting the anode and the cathode in such a positional relationship, the electrons flowing from the cathode toward the anode in the conductive fluid can also be thermally transported, and the cooling efficiency can be further improved.

The substrate may be formed of silicon.
By selecting silicon having a high thermal conductivity and easy processing and electrode formation as a base material, a power supply device can be manufactured using a general semiconductor manufacturing process.

The base may be formed integrally with the semiconductor integrated circuit in a silicon substrate on which the semiconductor integrated circuit is formed.
By forming the base body integrally with the semiconductor integrated circuit, heat loss at the adhesive surface between the semiconductor integrated circuit and the base body is reduced, and more efficient cooling can be performed.

The conductive fluid may include a liquid having a boiling point near the operating temperature of the semiconductor integrated circuit or its peripheral devices. The power supply system further includes an auxiliary pump that converts heat energy generated from the semiconductor integrated circuit or its peripheral device into energy for vaporizing the liquid, thereby converting the conductive fluid into kinetic energy for flowing through the flow path. You may prepare.
The conductive fluid is expanded when passing through the flow path in the substrate, and an auxiliary pump using a Rankine cycle (vapor cycle) is used as a heat source for a semiconductor integrated circuit, a peripheral power supply device, etc. A heat source can be used as power for the conductive fluid.

A load circuit other than the semiconductor integrated circuit may be driven by an electromotive force generated between the anode and the cathode.
Instead of the semiconductor integrated circuit to be cooled or together with the semiconductor integrated circuit, another load circuit can be driven by an electromotive force generated between the cathode and the anode.

  You may further provide the power supply which outputs the drive voltage for driving a semiconductor integrated circuit. The semiconductor integrated circuit may be driven by either a driving voltage output from a power supply or an electromotive force generated between the anode and the cathode.

When the electromotive force generated between the anode and the cathode is lower than a predetermined threshold value, the semiconductor integrated circuit may be driven by a driving voltage output from a power source.
When a voltage necessary for driving the semiconductor integrated circuit cannot be obtained as an electromotive force generated between the anode and the cathode, the semiconductor integrated circuit can be stably driven by switching to the power source.

You may further provide the control part which detects the electromotive force which generate | occur | produces between an anode and a cathode, and controls the speed | rate of a conductive fluid so that an electromotive force may approach a predetermined voltage value.
Since the electromotive force generated between the anode and the cathode depends on the speed of the conductive fluid, a stable electromotive force can be obtained by feedback-controlling the speed based on the electromotive force.

A temperature detection unit that detects the temperature of the semiconductor integrated circuit; and a control unit that controls the speed of the conductive fluid based on the temperature of the semiconductor integrated circuit detected by the temperature detection unit. The lower the temperature of the integrated circuit, the lower the speed of the conductive fluid.
In this case, when the temperature of the semiconductor integrated circuit is low, the power consumption of the entire system can be reduced by reducing the cooling capacity.

  Another aspect of the present invention is a power supply apparatus. This power supply apparatus includes a base body in which a flow path through which a conductive fluid flows is formed, and an anode and a cathode provided so as to sandwich the flow path. This power supply device drives a semiconductor integrated circuit to be driven by an electromotive force generated between an anode and a cathode by an interaction between a conductive fluid and a magnetic field applied to the conductive fluid.

  According to this aspect, the conductive fluid and the magnetic field interact in the flow path inside the substrate, and an electromotive force is generated between the cathode and the anode based on Faraday's law of electromagnetic induction. Can be driven.

The power supply apparatus may further include a magnet that applies a magnetic field to the conductive fluid.
The flow path may have a microchannel structure, and a plurality of flow paths may be formed adjacent to each other in the magnetic field application direction.

Yet another embodiment of the present invention is an electronic circuit driving method. In this electronic circuit driving method, the kinetic energy of a cooling medium for cooling the electronic circuit is converted into electric energy, and the electronic circuit is driven by the electric energy.
According to this aspect, by converting a part of the kinetic energy of the cooling medium into electric energy, it is possible to simultaneously cool the electronic circuit and supply power.

Yet another embodiment of the present invention is also an electronic circuit driving method. In this electronic circuit driving method, an electronic circuit to be cooled is driven by an electromotive force generated by an interaction between a conductive fluid for cooling the electronic circuit to be driven and a magnetic field applied to the conductive fluid.
According to this aspect, by selecting a conductive fluid as the cooling medium and applying a magnetic field to the conductive fluid, the kinetic energy of the conductive fluid is converted into electric energy based on Faraday's law of electromagnetic induction, and Electric power is generated. By utilizing this electromotive force, the electronic circuit to be cooled can be driven.

Yet another embodiment of the present invention is also an electronic circuit driving method. In this electronic circuit driving method, an electromotive force generated by the interaction between a conductive fluid circulated to cool an electronic circuit to be driven and a magnetic field applied to the conductive fluid is used as a main power source for driving the electronic circuit. It is used as an auxiliary power source to supplement the power supplied from
According to this aspect, the stability of the circuit can be improved by preparing the main power source in advance and using the above-described electromotive force as the auxiliary power source.

  Hereinafter, these aspects of the invention will be described in detail based on the embodiments.

A power supply system according to an embodiment of the present invention cools a semiconductor integrated circuit and simultaneously supplies driving power to the semiconductor integrated circuit.
FIG. 1 shows an overall configuration of a power supply system 100 according to an embodiment. The power supply system 100 includes an electromotive cooling head 10, a pump 14, a transport pipe 16, and a cooling device 18.

  The electromotive cooling head 10 is fixed in close contact with the semiconductor integrated circuit 12, deprives the semiconductor integrated circuit 12 of the amount of heat Q, and supplies the electromotive force Es. As will be described later, the electromotive cooling head 10 is provided with a base body having a flow passage through which a cooling medium can flow, and is connected to the transport pipe 16 at both ends. As the cooling medium, a conductive fluid is selected as described later. The electromotive cooling head 10 functions as a power supply device that supplies power to the semiconductor integrated circuit 12.

  By driving the pump 14, the cooling medium is circulated through the transport pipe 16 and the flow path inside the base body of the electromotive cooling head 10. The cooling medium whose temperature has risen due to the amount of heat Q taken from the semiconductor integrated circuit 12 in the electromotive cooling head 10 is cooled by the cooling device 18. The cooling device 18 is constituted by, for example, a heat sink, an air cooling fan, a Peltier element, or a combination thereof, and takes the heat quantity Q ′ from the cooling medium circulating in the transport pipe 16. What is necessary is just to comprise this pump 14 with the pump which circulates a fluid mechanically.

  As described above, the power supply system 100 according to the present embodiment cools the semiconductor integrated circuit 12 by circulating the cooling medium through the electromotive cooling head 10 fixed to the semiconductor integrated circuit 12.

FIG. 2 shows a cross-sectional configuration of the electromotive cooling head 10 and a connection state with the semiconductor integrated circuit 12.
The semiconductor integrated circuit 12 is a flip chip having a BGA (Ball Grid Array) structure, and is connected to the printed circuit board 20 via solder balls 22.
The electromotive cooling head 10 is in close contact so as to cover the back surface of the semiconductor integrated circuit 12. The semiconductor integrated circuit 12 includes a power supply voltage terminal Vdd and a ground terminal GND on the back surface thereof, and is driven by an electromotive force Es generated in the electromotive cooling head 10.

The electromotive cooling head 10 includes a base body 40, an N pole magnet 50, and an S pole magnet 52. FIG. 3 is a plan view of the electromotive cooling head 10 as viewed from above.
As shown in FIG. 2, flow paths 42 are formed as a plurality of microchannels inside the base body 40, and the cooling medium supplied from the transport pipe 16 flows from the front of the paper toward the back. The flow path 42 is provided so as to cover the heat generating portion of the semiconductor integrated circuit 12. A cooling medium flows in the flow path 42 in the direction shown in FIG.

  The N-pole magnet 50 and the S-pole magnet 52 are provided so as to sandwich the electromotive cooling head 10 in order to apply a magnetic field perpendicular to the flow direction of the cooling medium, that is, the direction of the flow passage. The N-pole magnet 50 and the S-pole magnet 52 generate a magnetic field B from the left side to the right side of the drawing. These magnets may be permanent magnets.

  Returning to FIG. A plurality of anodes 44 and cathodes 46 are provided on two inner surfaces of the channel 42 provided in the base 40 so as to sandwich the channel on two opposing surfaces parallel to the direction in which the magnetic field B is applied. The anodes 44 provided on the upper surface of the inner wall of the channel 42 and the cathodes 46 provided on the lower surface of the inner wall are electrically connected to each other, and are connected to the power supply voltage terminal Vdd and the ground terminal GND of the semiconductor integrated circuit 12. .

  The base 40 is preferably made of a material having good thermal conductivity. Further, the anode and cathode terminals provided on the inner wall of the flow path 42 formed in the base 40 are made of a metal material such as copper. Accordingly, when a semiconductor, particularly silicon, is used as the material of the base body 40, the base body 40 can be manufactured using a silicon semiconductor manufacturing process. A process for manufacturing such a microchannel and forming an electrode will not be described in detail because a known technique related to MEMS (Micro Electro Mechanical System) can be used.

  Several forms of connection between the substrate 40 and the semiconductor integrated circuit 12 are possible. When the base 40 and the semiconductor integrated circuit 12 are manufactured separately, as shown in FIG. 2, they are physically connected by solder bumps or the like, or pressure is applied between the electrode of the base 40 and the electrode of the semiconductor integrated circuit 12. They may be contacted or connected by wire bonding or the like.

  FIG. 4 is a diagram showing a modification of the power supply system of FIG. When silicon is selected as the material of the base body 40, the semiconductor integrated circuit 12 and the base body 40 may be integrally formed on the same silicon chip 200 as indicated by a broken line in FIG. In this case, there is no adhesive surface between the semiconductor integrated circuit 12 and the base 40, and heat loss is reduced as compared with the case of FIG. 1, so that more efficient cooling can be performed.

The operation of the power supply system 100 configured as described above will be described with reference to FIG.
The flow path 42 and the transport pipe 16 are filled with a conductive fluid as a cooling medium. Examples of the conductive fluid include liquid metals such as mercury, indium alloys, germanium alloys, bismuth alloys, and NaK. This conductive fluid transports heat generated from the semiconductor integrated circuit 12 and at the same time generates an electromotive force by interaction with a magnetic field.
FIG. 5 is a diagram illustrating a state of interaction between the conductive fluid and the magnetic field in the flow path 42.

  In the flow path 42, the conductive fluid flows at a velocity u in the x-axis direction. A magnetic field is applied to the flow path 42 at a magnetic flux density B in the direction opposite to the z axis by the N pole magnet 50 and the S pole magnet 52. When a conductive fluid flows in a magnetic field as shown in FIG. 5, an electromotive force Es = u × B is generated in a direction perpendicular to the fluid velocity u and the magnetic flux density B according to Faraday's law of electromagnetic induction. The electromotive force Es can be taken out from the anode 44 and the cathode 46 and supplied as a driving voltage for the semiconductor integrated circuit 12.

In the power supply system 100, the power necessary for driving the conductive fluid by the pump 14 can be estimated as follows.
The amount of heat Q [W] that can be transported by the conductive fluid flowing in the flow path 42 constituting the microchannel is represented by Q = Cp × g ′ × ΔT = ρ × Cp × V ′ × ΔT. Here, the constants are the heat capacity Cp [J / kg / K], the mass flow rate g [kg], the density ρ [m ³ / kg], the volume flow rate V [m ³ / s], and the velocity u, respectively. [M / s] represents a temperature difference ΔT [K] before and after passing through the microchannel. “′” Means time differentiation of a physical quantity. Therefore, in order to transport the heat quantity Qchip generated from the semiconductor integrated circuit 12 by the conductive fluid, V ′ ≧ Qchip / (ρ × Cp × ΔT) is required as the time differential V ′ of the volume flow rate V.

  When the number of microchannels is N and the cross-sectional area per channel is Ach, the total cross-sectional area of the conductive fluid is given by N × Ach. Since the velocity u of the conductive fluid flowing in the microchannel is given by u = V ′ / (N × Ach), by setting u ≧ Qchip / (N × Ach × ρ × Cp × ΔT), the semiconductor integration The amount of heat generated from the circuit 12 can be transported.

Furthermore, flow resistance [Delta] P of the microchannel, because given in ^{ΔP = ρ × u 2/2} ,, when flowing conductive fluid at a velocity u in the interior microchannel, the driving power Wch of conductive fluid [W] is Only Wch = N × Ach × u × ΔP is required.

On the other hand, the electromotive force Es [V] in the electromotive cooling head 10 is proportional to the magnetic flux B [T] and the velocity u of the conductive fluid, and is given by E = u × B. The internal electrical resistance Rint [Ω] of the conductive fluid between the anode 44 and the cathode 46 is the electrical resistivity σ [Ω · m] of the fluid, the distance d [m] between the anode 44 and the cathode 46, and the electrode area S [m ² ]. ], Rint = σ × d / S. Therefore, if the internal resistance of the semiconductor integrated circuit 12 to be supplied with power is Rext [Ω], the current I flowing through the semiconductor integrated circuit 12 is I = Es / (Rin + Rext). As a result, the power consumption in the semiconductor integrated circuit 12 is Pchip = Es ² / (Rint + Rext).
Therefore, the power Win to be supplied to the conductive fluid by the pump 14 is the sum of the power supplied to the semiconductor integrated circuit 12 as an electromotive force and the power necessary to circulate in the microchannel. Considering the efficiency η of 12, Win ≧ Wch + η × Pchip = N × Ach × ρ / 2 × u ³ + η × B ² / (Rint + Rext) × u ² .

A design example when mercury is used as the conductive fluid is shown below. Considering the case where the amount of heat generated from the semiconductor integrated circuit 12 is Q and transported at ΔT = 28 ° C., the required mass flow rate is 2.13 g / s and the volume flow rate is 2.63 cc / s. If the number of channels constituting the microchannel is 70, the cross section of each channel is 70 μm × 70 μm, and the length is 0.8 cm, u = 0.94 m / s is required as the average speed of each channel. The
At this time, the flow resistance inside the microchannel is about 2 MPa. Thus, the driving power of the conductive fluid is Wch = 4.9W.

  An electromotive force Es obtained when a magnetic flux of B = 1.1 T is applied as a magnetic flux to a conductive fluid having a velocity u = 0.94 m / s is Es = 1.1V. When the electrical resistance value Rint is 0.1 mΩ and the chip-side internal resistance Rext = 1Ω, a total of 70 W of power can be supplied to the semiconductor integrated circuit 12.

  The speed u of the conductive fluid is decelerated in response to the deceleration force F = JB due to loss of energy due to electromotive force. Therefore, the pump 14 for driving the conductive fluid needs to flow the conductive fluid into the transport pipe 16 so as to cancel out the deceleration force. That is, the power of Win = Wchip + Wch = 74.9 W may be supplied to the conductive fluid by the pump 14. Actually, in addition to the electric power Win, electric power for circulating the conductive fluid in the transport pipe 16 is required.

  As described above, according to the power supply system 100 according to the present embodiment, the electromotive cooling head 10 removes heat from the semiconductor integrated circuit 12 and at the same time uses the electroconductive fluid as the cooling medium. 10, the electromotive force Es can be generated to supply power to the semiconductor integrated circuit 12.

  In addition, power is supplied through the electrodes Vdd and GND provided on the semiconductor integrated circuit 12 side of the electromotive cooling head 10, but these electrodes are not restricted by other electrodes, so that the area thereof is conventionally reduced. The BGA package structure can be made wider, and the problem of current capacity per terminal, which has been a problem with the conventional BGA package structure, can be solved.

  In this power supply system 100, it is not necessary to use conventional wiring for power supply to the semiconductor integrated circuit 12, so that dangers such as disconnection and short circuit can be reduced. In addition, the problem of migration, which was a problem in power supply by wiring, can be solved.

  Hereinafter, based on the power supply system 100, a modification example in which a technique for operating the circuit more stably or performing efficient cooling will be described.

FIG. 6 shows a first modification of the power supply system 100 according to the present embodiment.
The calorific value Q of the semiconductor integrated circuit 12 varies greatly depending on the operation state of the circuit. Therefore, the cooling capacity of the cooling device 18 may be controlled while the temperature T of the semiconductor integrated circuit 12 is monitored.
FIG. 6 shows a configuration example of the power supply system 100 a that controls the cooling capacity of the cooling device 18 according to the temperature of the semiconductor integrated circuit 12. The power supply system 100 a includes an electromotive cooling head 10, a pump 14, a transport pipe 16, a cooling device 18, a temperature detection unit 60, and a cooling control unit 62. Hereinafter, in the modification of the power supply system 100, the same components as those in FIGS.

The temperature detection unit 60 detects the temperature T of the semiconductor integrated circuit 12 using a thermocouple, an infrared sensor, or other temperature detection means. The temperature detection unit 60 outputs a detection signal Vt corresponding to the temperature T of the semiconductor integrated circuit 12 to the cooling device 18.
The cooling control unit 62 generates and outputs a control signal Vcnt for controlling the cooling capacity of the cooling device 18 based on the detection signal Vt. As a method of controlling the cooling capacity in the cooling controller 62, the cooling capacity is increased when the detection signal Vt is equal to or higher than a predetermined threshold value, that is, when the temperature T of the semiconductor integrated circuit 12 is equal to or higher than the predetermined threshold value. Alternatively, the cooling capacity may be feedback controlled so that the temperature T of the semiconductor integrated circuit 12 is constant. When the cooling device 18 is constituted by an air cooling fan, the rotation number of the air cooling fan may be changed by the control signal Vcnt. When the cooling device 18 is constituted by a Peltier element, the voltage applied to the element is changed. Can control the cooling capacity.

  In this way, by controlling the cooling capacity of the cooling device 18 according to the temperature T of the semiconductor integrated circuit 12, stable cooling can be performed and the semiconductor integrated circuit 12 can be operated stably. Further, when the heat generation amount of the semiconductor integrated circuit 12 is small, the power consumption in the cooling device 18 can be reduced by reducing the driving capability of the cooling device 18.

  FIG. 7 shows a second modification of the power supply system. The power supply system 100b of FIG. 7 includes an electromotive force detection unit 64, a changeover switch SW, and a power supply 66. In the power supply system 100b, the electromotive force obtained from the electromotive cooling head 10 until the speed u of the conductive fluid reaches a required value, such as immediately after the pump 14 starts driving the conductive fluid in the transport pipe 16. As Es, a case where a voltage necessary for stably operating the semiconductor integrated circuit 12 cannot be obtained is also assumed. 7 switches the power supply source to the semiconductor integrated circuit 12 to the power supply 66 when the electromotive force Es obtained from the electromotive cooling head 10 is lower than the threshold voltage.

The electromotive force detector 64 detects the electromotive force Es obtained from the electromotive cooling head 10 and compares it with a predetermined threshold voltage Vth. This threshold voltage Vth is set higher than a voltage necessary for stable operation of the semiconductor integrated circuit 12. The electromotive force detection unit 64 outputs a switching signal Vsw to the switch SW.
The electromotive force detection unit 64 turns on the switch SW on the electromotive cooling head 10 side when Es> Vth, and turns on the switch SW on the power supply 66 side when Es <Vth. The voltage Vdd ′ output from the power supply 66 is set higher than the threshold voltage Vth.

  In the power supply system 100b configured as described above, the drive voltage applied to the semiconductor integrated circuit 12 does not become lower than the predetermined threshold voltage Vth, so that the circuit can be operated more stably.

FIG. 8 shows a third modification of the power supply system. The power supply system 100 c stabilizes the electromotive force Es in the electromotive cooling head 10 by adjusting the speed u of the conductive fluid by the pump 14.
The power supply system 100c includes a pump control unit 70 in addition to the power supply system 100 of FIG. The pump control unit 70 includes an operational amplifier 72 and a drive voltage generation unit 74.

  The reference voltage Vref is input to the non-inverting input terminal of the operational amplifier 72, and the electromotive force Es supplied to the semiconductor integrated circuit 12 is input to the inverting input terminal. The error voltage Verr output from the operational amplifier 72 is input to the pump 14.

  The drive voltage generation unit 74 controls the drive capability of the pump 14 based on the error voltage Verr output from the operational amplifier 72. The speed u of the conductive fluid is controlled by the driving ability of the pump 14. In the operational amplifier 72, the error voltage Verr is feedback-controlled so that the two voltages inputted to the inverting input terminal and the non-inverting input terminal are equal, and the velocity u of the conductive fluid is adjusted. Since the electromotive force Es is proportional to the velocity u of the conductive fluid, the electromotive force Es can be stabilized so that Es = Vref.

  In general, when the voltage supplied to the semiconductor integrated circuit 12 is stabilized, a linear regulator or the like is used. However, in this power supply system 100, the electromotive force Es can be obtained without using a linear regulator. By detecting and feedback-controlling the velocity u of the conductive fluid, the electromotive force Es can be stabilized at a desired reference voltage Vref, and a stable voltage can be supplied to the semiconductor integrated circuit 12.

  FIG. 9 shows a fourth modification of the power supply system. The power supply system 100d in FIG. 9 includes a pump control unit 70 that controls the drive capability of the pump 14 as in the power supply system 100c in FIG. 8, but the pump 14 is based on the temperature T of the semiconductor integrated circuit 12. 8 is different from FIG. 8 in that the driving ability is controlled.

In the power supply system 100d, the pump control unit 70 is configured to operate the pump 14 when the voltage Vt output from the temperature detection unit 60 is equal to or higher than a predetermined voltage, that is, when the semiconductor integrated circuit 12 exceeds a predetermined threshold temperature. To increase the speed u of the conductive fluid in the electromotive cooling head 10. Alternatively, the pump 14 may be feedback controlled so that the voltage Vt output from the temperature detection unit 60 approaches a predetermined voltage, that is, the temperature T of the semiconductor integrated circuit 12 approaches a predetermined temperature.
By configuring the power supply system in this way, it is possible to prevent the temperature T of the semiconductor integrated circuit 12 from becoming higher than a predetermined temperature, thereby suppressing thermal runaway of the semiconductor integrated circuit 12 and stabilizing the circuit. Can be operated. Further, when the heat generation amount in the semiconductor integrated circuit 12 is small and the temperature T of the semiconductor integrated circuit 12 is low, the power consumption of the pump 14 can be reduced by reducing the driving capability of the pump 14, so that Power consumption will be reduced.

  In the power supply system 100 and its modification, the pump 14 may be a pump known as an MHD (Magneto Hydrodynamics) pump. In the power supply system 100 according to the present embodiment, a conductive fluid is used as a cooling medium. Therefore, a magnetic field is applied perpendicular to the direction in which the conductive fluid flows, and an electric field is applied perpendicular to the magnetic field and the flow direction. When applied, the conductive fluid is accelerated by receiving the Lorentz force. The principle of this MHD pump utilizes the characteristics contrary to the generator shown in FIG. According to the MHD pump, the acceleration, that is, the speed can be changed by the electric field applied to the conductive fluid, and the design can be made more compact than the mechanical pump.

  As the cooling medium, a liquid that vaporizes to a slightly higher degree than room temperature, such as water or FC, may be mixed in the conductive fluid. Further, an auxiliary pump is installed in the vicinity of the electromotive cooling head 10. The cooling medium removes heat from the semiconductor integrated circuit 12 when passing through the flow path 42 in the electromotive cooling head 10. The liquid mixed in the cooling medium is vaporized by the heat taken away. Since the cooling medium expands by the vaporization of the liquid, the conductive fluid can be circulated through the flow path 42 by converting the heat energy into kinetic energy by the auxiliary pump. As such an auxiliary pump, a heat engine using a Rankine cycle can be used. Further, the heat source serving as a power source for the auxiliary pump is not limited to the semiconductor integrated circuit 12, and heat generated by a power source of a set on which the semiconductor integrated circuit 12 is mounted may be used.

  The above embodiment and its modifications are exemplifications, and it will be understood by those skilled in the art that various modifications can be made to the combinations of the respective components and processing processes, and such modifications are also within the scope of the present invention. It is understood.

For example, the techniques used in the first to fourth modifications can be arbitrarily combined.
When the techniques used in the first modification and the fourth modification are combined, a more stable cooling operation can be performed by using a common temperature detection unit. Similarly, when the techniques used in the second modification and the third modification are combined, the electromotive force detection unit 64 can be shared, and the power supply to the semiconductor integrated circuit 12 can be further stabilized. Can do.
Further, when the first modification and the third modification are combined, the speed of the conductive fluid is controlled by the pump 14 while controlling the temperature T of the semiconductor integrated circuit 12 by adjusting the cooling capacity of the cooling device 18. The electromotive force Es in the electromotive cooling head 10 can be stably generated by adjusting u.

It is a figure which shows the whole structure of the electric power supply system which concerns on embodiment. It is a figure which shows the cross-sectional structure of an electromotive cooling head, and a connection state with a semiconductor integrated circuit. It is the top view which looked at the electromotive cooling head of FIG. 2 from upper direction. It is a figure which shows the modification of the electric power supply system of FIG. It is a figure which shows the mode of interaction of the electroconductive fluid and magnetic field in a flow path. It is a figure which shows the 1st modification of an electric power supply system. It is a figure which shows the 2nd modification of an electric power supply system. It is a figure which shows the 3rd modification of an electric power supply system. It is a figure which shows the 4th modification of an electric power supply system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Electric power supply system, 10 Electromotive cooling head, 12 Semiconductor integrated circuit, 14 Pump, 16 Transport pipe, 18 Cooling device, 42 Flow path, 44 Anode, 46 Cathode, 40 Base, 50 N pole magnet, 52 S pole magnet, 60 temperature detector, 62 cooling controller, 64 electromotive force detector, 70 pump controller, 72 operational amplifier, 74 drive voltage generator.

Claims (16)

A base body in which a flow path is formed;
A pump that circulates a conductive fluid in a flow path drilled in the base;
A magnet for applying a magnetic field perpendicular to the flow direction of the conductive fluid;
An anode and a cathode provided so as to sandwich the flow path between two opposing surfaces parallel to the application direction of the magnetic field;
With
The semiconductor integrated circuit to be driven is driven by an electromotive force generated between the anode and the cathode, and the semiconductor integrated circuit is cooled using the conductive fluid as a cooling medium,
The anode and the cathode are each provided in parallel with the semiconductor integrated circuit, the anode is provided on the semiconductor integrated circuit side of the flow path, and the cathode is the semiconductor integrated circuit of the flow path. A power supply system provided on the opposite side of the circuit . The base is fixed in close contact with the semiconductor integrated circuit;
The flow path is perforated in a region close to a heat generation point of the semiconductor integrated circuit,
The power supply system according to claim 1, further comprising a cooling device that cools the conductive fluid.   The power supply system according to claim 1, wherein the flow path has a microchannel structure, and a plurality of the flow paths are formed adjacent to each other in the application direction of the magnetic field. A temperature detector for detecting the temperature of the semiconductor integrated circuit;
A cooling controller that controls the cooling capacity of the cooling device based on the temperature of the semiconductor integrated circuit detected by the temperature detector;
The power supply system according to claim 2, further comprising:   The power supply system according to claim 1, wherein the anode and the cathode are connected to a power supply voltage terminal and a fixed voltage terminal of the semiconductor integrated circuit, respectively.   The power supply system according to claim 1, wherein the base is made of silicon. The power supply system according to claim 6 , wherein the base is formed integrally with the semiconductor integrated circuit in a silicon substrate on which the semiconductor integrated circuit is formed. The conductive fluid includes a liquid having a boiling point near the operating temperature of the semiconductor integrated circuit or its peripheral device,
The apparatus further includes an auxiliary pump that converts thermal energy generated from the semiconductor integrated circuit or its peripheral device into energy for vaporizing the liquid, thereby converting the conductive fluid into kinetic energy for flowing through the flow path. The power supply system according to claim 1.   The power supply system according to claim 1, wherein a load circuit other than the semiconductor integrated circuit is driven by an electromotive force generated between the anode and the cathode. A power supply for outputting a driving voltage for driving the semiconductor integrated circuit;
The power supply system according to claim 1, wherein the semiconductor integrated circuit is driven by either a drive voltage output from the power supply or an electromotive force generated between the anode and the cathode. 11. The power supply according to claim 10 , wherein when the electromotive force generated between the anode and the cathode is lower than a predetermined threshold value, the semiconductor integrated circuit is driven by a driving voltage output from the power source. system.   The apparatus according to claim 1, further comprising a control unit that detects an electromotive force generated between the anode and the cathode and controls a speed of the conductive fluid so that the electromotive force approaches a predetermined voltage value. The power supply system described. A temperature detector for detecting the temperature of the semiconductor integrated circuit;
A control unit for controlling the speed of the conductive fluid based on the temperature of the semiconductor integrated circuit detected by the temperature detection unit;
The power supply system according to claim 1, further comprising: the controller that decreases the speed of the conductive fluid as the temperature of the semiconductor integrated circuit is lower. A base body with a flow path through which a conductive fluid flows; and
An anode and a cathode provided to sandwich the flow path,
The semiconductor integrated circuit to be driven is driven by an electromotive force generated between the anode and the cathode by the interaction between the conductive fluid and a magnetic field applied to the conductive fluid, and the conductive fluid is used as a cooling medium. Cooling the semiconductor integrated circuit;
The anode and the cathode are each provided in parallel with the semiconductor integrated circuit, the anode is provided on the semiconductor integrated circuit side of the flow path, and the cathode is the semiconductor integrated circuit of the flow path. A power supply device provided on the opposite side of the circuit . The power supply apparatus according to claim 14 , further comprising a magnet that applies a magnetic field to the conductive fluid. The power supply device according to claim 14 , wherein the flow path has a microchannel structure, and a plurality of the flow paths are formed adjacent to each other in the application direction of the magnetic field.

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